To: Honorable Mayor and Members of Town Council
From: Mark Marlowe, P.E., Director of Castle Rock Water
Title
Resolution Approving a Construction Contract with Garney Companies, Inc. for the Castle Rock Water Improvements Projects (various locations around Town)
Body
________________________________________________________________________________
Executive Summary
Castle Rock Water is seeking Town Council approval of a construction contract (Attachment A) with Garney Companies, Inc. for the Castle Rock Water Improvements Project. Replacement and rehabilitation of aging infrastructure is one of the most important issues for Castle Rock Water to continually address, and this effort will only grow as Castle Rock Water’s $550 million plus of infrastructure ages. To make things more challenging much of Castle Rock Water’s infrastructure was installed during short periods of high growth (see Attachment C which is Figure 3.2 excerpted from the 2017 Water Master Plan),
This makes it even more critical that we spread out the costs for rehabilitation and replacement over time so that big chunks of this work don’t come due all at once. This rehabilitation and replacement project consists of the replacement of the Baldwin pressure reducing valve (PRV), the Canyon PRV, Meadows Water Treatment Plant Transmission Mains Butterfly Valve Replacements, and the Maher Force Main Manhole Replacement (see Attachment B for location map). Garney submitted the lowest responsive bid for a total construction cost of $297,830. Staff also requests approval for a 10 percent Town-managed contingency of $29,783, for a total project authorization of $327,614.
Discussion
Castle Rock Water staff has identified a number of facilities that need to be rehabilitated. The Castle Rock Water Improvements Project has combined the required improvements at four facilities into a single project. The projects were combined into a single project to create a more desirable project for contractors to bid on and to gain economies of scale.
This project includes the replacement of two existing PRV vaults: the Canyon PRV located near the intersection of Canyon Drive and Oakwood Drive and the Baldwin PRV located near the intersection of Baldwin Park Road and S. Valley Drive. Both PRV vaults were constructed in the late 1980’s. Both vaults are not constructed per today’s Town standards. The vaults were constructed without solid floors, which allows groundwater to periodically flood the vaults. The flooding has caused corrosion to the valves and piping within the vaults. The design of the existing vaults also makes repairs difficult due to a lack of adequate working space. The new vaults will be constructed with adequate space to work in and with solid concrete floors. In addition, each vault will include a sump to collect and remove any groundwater or leaks from piping.
This project also includes the replacement of two 18-inch direct bury butterfly valves on the Meadows Water Treatment Plant discharge transmission mains. The Meadows Water Treatment Plant was constructed in 1987 and one of the 18-inch butterfly valves has failed and needs to be replaced. Currently the valves are not accessible without excavation because they are buried. Staff determined that the second valve should be replaced since it is near the end of its useful life. This project will also include the installation of a new vault over these valves to provide access for future maintenance of these valves.
The fourth item included in this project is the replacement of the discharge manhole for the Maher Force Main, which was constructed in 2002 to serve the Sapphire Pointe subdivision. Hydrogen sulfide is formed in anaerobic environments, such as wastewater force mains. When the wastewater in the force main is discharged into the receiving manhole, the hydrogen sulfide gas is released into the air within the manhole. This gas is corrosive to the concrete manhole, and it has badly damaged this manhole. As such, the existing discharge manhole needs to be replaced, due to this damage. The new manhole will be epoxy-lined to minimize future damage from hydrogen sulfide gases. This past summer Operations staff added the ability to dose corrosion control inhibitors to the wastewater discharge, which will help minimize formation of corrosive gases and odors.
The request for bids for the project was sent to five qualified contractors. Bids were received by three contractors, as summarized in the table below. The Engineer’s estimate was $384,642. The low bid was received by Garney and is considered a responsive bid.
|
Consultant |
Bid Amount |
|
Garney |
$297,830 |
|
Global |
$317,690 |
|
T. Lowell |
$475,000 |
|
53 Corp. |
No Bid |
|
Velocity |
No Bid |
Budget Impact
Funding for this project is available in the approved 2018 Budget. The Baldwin PRV and Canyon PRV, will be funded from the Distribution System Upgrades (Account No. 210-4275-442-75-38) which has $250,000 available. The Meadows Valve Replacement will be funded from the Meadows WTP Valves and Actuators (Account No. 210-4275-442-75-10) which has $200,000 available. The Maher Force Main manhole will be funded from the Sewer Line Rehab (Account No. 213-4575-445-75-62) which has $350,000 available. The Garney bid is $297,830. Staff requests an additional $29,783 (Town-managed 10 percent contingency) be authorized for a total project authorization of $327,614.
|
Project Account |
Amount |
Contingency |
Total |
|
210-4275-442.75-38 |
$202,450 |
$20,245 |
$222,695 |
|
210-4275-442.75-10 |
$52,100 |
$5,210 |
$57,310 |
|
213-4575-445.75-62 |
$43,281 |
$4,328 |
$47,609 |
|
TOTAL |
$297,831 |
$29,783 |
$327,614 |
Staff Recommendation
Staff recommends Town Council approval of the construction contract between the Town and Garney Companies, Inc. for the construction of the Castle Rock Water Improvements Project in the amount of $297,830 plus a 10 percent Town-managed contingency of $29,783 for a total authorization in the amount of $327,614.
Proposed Motion
“I move to approve the Resolution as introduced by title.”
Attachments
Attachment A: Resolution
Exhibit 1: Construction contract
Attachment B: Location map
Attachment C: Figure 3.2 f